李 欣，刘 涛,张树山,孙福波,刘建平  

    摘要：锻钢材料以其高强度、高性能、热膨胀系数低等特点，已成为目前一种新型活塞材料，但由于其密度大、硬度较高，因而与传统铝合金活塞的加工方式有着很大的区别。锻钢活塞止口加工借鉴传统的铝合金活塞加工方式，以燃烧室外圆及顶面定位进行加工，但活塞外圆与止口同轴度严重超差，因此对加工方式进行了改进。

    关键词： 锻钢活塞，加工流程，内腔定位

    Abstract: Forged steel material has these factors like high strength, high performance, and lower expansion coefficient. This material has being applied widely to manufacture pistons. The method to machine the piston made of the forged steel material is different from that to machine the piston made of aluminum alloy. When the locating flange of the forged steel piston is machined by the traditional machining process, the exterior roundness and the top surface of the combustion chamber are used as a locating reference. This way may cause the coaxiality between the exterior roundness and the locating flange to exceed the tolerance, so the machining method is improved. 

    Keywords: Forged Steel Piston; Processing Flow; In-cavity Locating